Electrical Problem- Gen 3 Alternator replacement

[mknz]

Smart chargers won't necessarily give you 20A though, you should still use one though since you have a maintenance free battery.

13.5V while running is concerning. Go test the voltage across the alternator, if it's also 13.5V or near enough then it's the alternator. Else, you have a poor connection between the alternator and the battery.

Really, the minimum you want to see while running is 13.8V at the battery terminals.

[Benckj]

The 13.5v was after a quick charge using mains not from engine. When engine running there is no charge as it use to be 14+v. Definitely an alternator or circuit issue just need to find where. In my view alternators rarely give up after sitting idle for a month .

[Benckj]

Well managed to check underneath and all is well. Looked at another alternator I had for parts and think that my charger may have damaged the bridge rectifier inside alternator when I charged it overnight. I know the solder joints can give way as well as diodes fail. Going to order a 135amp model from States and swap out when it arrives. I will pull the old one down after that and try and confirm my theory. May be a simple fix but I’ll use as excuse to upgrade.

[Benckj]

Looked what arrived today!
Approx $200 +$42 shipping using Youshop. Not exactly fast but I wasn’t in a hurry to get. Now comes the fun bit, remove from top or bottom?

[GDII]

Looked what arrived today.
Approx $200 +$42 shipping using Youshop. Not exactly fast but I wasn’t in a hurry to get. Now come the gun bit. Remove from top or bottom?

I have been able to remove the alternator from the top on the GEN2 3SGE. Not sure how the GEN3 3SGTE manifold changes things. I feel the runner and plenum are heading towards the middle of the car more than the 3SGE does. I always take off the diag port off the fire wall, vacuum hose to the brake booster and a mounting plate on the manifold. The 3SGTE doesn't have this plate though. I pull it up using the pulley and have it rotated to fit. Best wrap it in a cloth so not to wreck the paint.

[tw2]

+1 I did all the same things. This will make it a piece of cake to remove forever more http://racerxfabrication.com/mr2-celica ... or-bracket

[Benckj]

Bugger r iPhone, can’t attach pics but will do on PC tomorrow.

Yea my thoughts are to pull from top even though I have a few extra bits to remove. Got car up on ramps so can get under to do the plug, bolts etc. Will also pull bracket as I seem to recall it was near impossible to wiggle around. Will also give me a chance to check and possibly re-tap adjustment bolt hole as it’s out by 5mm. Been through this before on my NA.

[Benckj]

Pics attached to post above now. Alternator looks to be decent quality and is completely new, not refurbished. Hope I can get onto this weekend.

[Benckj]

Limited progress with this PITA job. Managed to disconnect alternator including a stubborn electrical plug that took Hurcules effort to pull off. Now it sits above sub frame and will not fit through gap nor through space up top unless alternator holding bracket is removed. Started on removal of bracket as I saw this as the easiest alternative but after removal of the 3 upper nuts/bolt I found out the two on under side are obstructed by the CB joint for access. So that is where it stands, do I lower sub frame (exhaust still obscuring so may need to pull this as well) or persevere with the alternator bracket.

Sidenote; When I did the same with my NA a couple of years ago the alternator bracket was fairly easy to remove. The turbo unfortunately is more difficult either because of larger CV & axles or because the turbo uses a carrier bearing to support axle. Concerned that if the carrier bearing is disconnected from block to give me some bolt wiggle room I'll disturb the trans seal. Fun and games galore!

[4CylinderSpecial]

Limited progress with this PITA job. Managed to disconnect alternator including a stubborn electrical plug that took Hurcules effort to pull off. Now it sits above sub frame and will not fit through gap nor through space up top unless alternator holding bracket is removed. Started on removal of bracket as I saw this as the easiest alternative but after removal of the 3 upper nuts/bolt I found out the two on under side are obstructed by the CB joint for access. So that is where it stands, do I lower sub frame (exhaust still obscuring so may need to pull this as well) or persevere with the alternator bracket.

Hi Jim. When I replaced my intake manifold I removed my alternator for shits and gigs to inspect. There is ample space to fit alternator through bottom past subframe if you remove the manifold. I consider this easy to do but you might be more comfortable removing the subframe..

[Benckj]

I sort of looked at that option but discounted because of ignorance. Haven't pulled a MR2 intake manifold before but might be the best idea. Looked through my pics when dropped engine and nothing showing intake side.
As a bonus, I already have a full gen 3 gasket kit which may have all the bits I need? Would actually be nice to pull apart, clean and install with new gaskets. Hmmmmmmm...............

[4CylinderSpecial]

I sort of looked at that option but discounted because of ignorance. Haven't pulled a MR2 intake manifold before but might be the best idea. Looked through my pics when dropped engine and nothing showing intake side.
As a bonus, I already have a full gen 3 gasket kit which may have all the bits I need? Would actually be nice to pull apart, clean and install with new gaskets. Hmmmmmmm...............

It is surprisingly easy to do and depending on what you have is a matter of taking the throttle body off, undoing the electrical connectors and injectors/vacuum line and moving them out of the way and then undoing the nuts and bolts. I did it without reading a guide in around 1-2 hours and I was taking my time. Fortunately there isn't too much around there to confuse and mix up. Putting on fresh gaskets is a bonus

[Benckj]

I’ll look at again this weekend and make a call which way to go. Had TB and injectors our before but didn’t dive any deeper. My problem is that once I pull something apart I tend to improve it rather than simply replace. Even a simple maintenance job can turn into a project. Got too many projects on the go already! Thinking dremel out intake runners and injector seal replacement,..........

[Benckj]

Have reached a few stumbling blocks so not much progress with this 'little project'. To fair its a major PITA with the removal and installation of new alternator. Not sure if this is due to owning a gen 3, turbo or there is something else blocking my view of the job. Any suggestions appreciated.

Option A- pull alternator from top by removing alternator bracket which prevents extraction. Problem is that the 3 bolts can be removed from upper bracket and one below leaving one which intersects the RHS CV joint. Would need to pull axle before bolt can be extracted which requires dropping trans fluid, wheel hub assembly, carrier, bearing, etc.

Option B- drop alternator below by lowering sub frame. This may or may not work as axle could still be in the way as limited space between axle and exhaust flange. As an aftermarket exhaust installed this flange is closer to axle than OEM set-up. May require further work including full exhaust removal as well as sub frame (incl suspension components).

Option C- pull from top after removal of intake manifold. This appears to be quite easy as all bolts have relatively easy access. On closer inspection the A2W IC, throttle body and fuel rail must be removed first. This creates a huge amount of work to do as I like to replace seals, etc when re-installing. As the intake manifold has not been removed before it is possible to encounter bolts, or connections that cannot be extracted. Would generally prefer to do this when engine is dropped and on the bench. Not sure how well I can get intake to seal afterwards as space is limited.

Option D- drop engine far enough to pull alternator and check other components. I dropped the engine 3 years ago to install new turbo, replace cam belt, clutch, axle cages, seals & fluids. This would be the best option if I had several jobs to do but not really a fan of this amount of work for limited gains. Too many other home projects on the go to get this done in a reasonable time frame.

Option E- possible to reduce size of alternator by partially disassembly insitu. Would need to do same with installation of replacement. Not really sure if this is an option or not but may require investigation. I have a spare one to practice with.

[mknz]

I think A/B as they share work and give you two ways to go. It's also the least painful work IMO